I have studied all the above photos and studied the item in detail.
The beautiful red colour is the proper Ferrari red. All the mechanisms work perfectly and I've checked all the serial numbers.
I have now concluded that it is indeed not a Mk1 but it is instead an early MKII....
MOP.
Bike is the same apparently. Frame no. puts it as one of the first of the MkIIs the give away is also the brake callipers behind the fork legs whereas they are in front on MkIs. Never mind, it still looks, sounds and rides like a MkI so Proff is "not bovvered". Similar one sold by auction house in London recently, same year and spec (ie early MkII done to look as MkI) for £7,150!
<anorak>
the fork legs are interchangeable, but not the same. mk 1s have thinner walls. mk 2s also have air suspension valves in the fork tops. if you find air valves on a mk 1 it's prolly got later stanchions.
either type are reversible so the calipers are at the back. indeed, you will notice on such bikes, the drains are now at the front in what is clearly not the original place as designed.
the real giveaway with the forks is the distance between them. mk 2s are further apart & use a correspondingly different mudguard with bevelled edges. that's how i knew from the pictures that the bike had mk 2 forks, at least.
no mark 1 ever had a flap over the filler cap either.
other than that and the fairing, there is not much difference between the mk 1 and 2. different mounts for the instruments by the look of yours.
i reckon most 2s are now in mk 1 guise as they are much more sought after. oddly, in comparison to other makes, such transformations seem much less significant to guzzi owners generally.
sure, there is a difference in price but not the snobbery i'd have expected.
i reckon yours was priced a little cheap, and looks and sounds a very nice bike. just paint the black back onto the top and bottom* of the petrol tank and try and find an original seat.
at the risk of boring the shit out of everyone, i'll tell you the difference between the, so called "series 1 and series 2" 850 lemans (never officially a mk 1 of course).
series 1
very rare now. only made for a few months.
round rear light.
front indicators mounted on the frame.
plain heel plates on the footrest mounts.
series 2
oblong rear light.
front indicators mounted on the bottom fork yoke.
embossed heel plates on the footrest mounts.
if there are any other differences, i don't know what they are.
*paint it straight across like the factory did it. it's very tempting to follow the curve of the tank. lots do it that way, but it always looks bad.
Well done that man 
right up until she rams that mop up his nose
